# MIC_StartAutoSamplingAsync

## C Specification

  `#include <nitro/spi.h>`

      MICResult MIC_StartAutoSamplingAsync(
      const       MICAutoParam*       param,
                  MICCallback		callback,
                  void*		arg );

## Description

This function asynchronously starts microphone auto-sampling. This function issues a request to the ARM7 processor to start auto-sampling and returns to the place from which it was called without waiting for a response from the ARM7 processor.

To get the ARM7 process result, you need to use the `result` argument that gets passed to the user callback function.

If the input volume exceeds the minimum or maximum values, output data will be clamped. It is possible to set the input volume that can be sampled before hand using the `PM_SetAmpGain` function. Note that after the auto sampling starts, the input volume cannot be adjusted until the auto sampling process is stopped.

If this function fails, asynchronous operations are not performed and the callback function cannot be called.

Note: Do not operate other subprocessor peripherals (SPI device) during the auto-sampling process.

It is possible to execute the one time sampling of the touch panel with `TP_RequestCalibratedSampling`, `TP_RequestRawSampling`, and `TP_RequestSamplingAsync` functions during the microphone auto sampling process.

However, the touch panel is executed the next time the microphone sampling ends, and it may take longer than usual for the touch panel to respond.

## Arguments

param | Specifies a pointer to the MICAutoParam type auto-sampling structure.
callback | Specifies a pointer to the callback function.
arg | Specifies the argument to pass to the callback function.

## Return Values

0 if request succeeds.
Non-zero value if request fails.

## See Also

`MIC_StartAutoSampling`, `MIC_StopAutoSampling`, `MIC_StopAutoSamplingAsync`, `PM_SetAmpGain`

## Revision History

09/17/2004 Changes the type of the argument param
08/10/2001 Added the description to the touch panel sampling during the microphone auto sampling process. Added the description to the input volume.
06/01/2004 Initial version